This collection reflects on developments in the field of Systemic Functional Linguistics (SFL) as embodied in the work of Christian M.I.M. Matthiessen, highlighting his diverse contributions to the field from theoretical and applied perspectives. The book surveys Matthiessen’s academic career and illustrates the myriad ways in which his work has reverberated through to current innovations in SFL research. The book also exhibits his theoretical contributions to major linguistic topics and his influence on the development of SFL. Written by some of the world’s foremost scholars in the field, chapters cover such topics as theories of SFL and its applications in different domains as well as the developmental trajectories of SFL in major geographic areas. Addressing the key issues in SFL through the lens of Matthiessen’s career, this book is an accessible resource for students and scholars in systemic functional linguistics, as well as those interested in the systemic functional approach in related areas within linguistics.